This invention relates to in general to vehicle tire inflation and, in particular, to a vehicle central tire inflation system.
A central tire inflation system (CTIS) is an onboard tire inflation (and typically deflation) system which is operative to monitor and adjust the air pressure in the associated tires of the vehicle.
One example of a CTIS is disclosed in U.S. Pat. No. 5,253,687 to Beverly et al. In the Beverly et al. patent, the CTIS includes a separate wheel valve assembly affixed to each vehicle wheel. The wheel valve assembly includes an inlet port connected to an air control circuit of the CTIS, an outlet port connected to an inflatable volume tire chamber, and an exhaust port connected to atmosphere. In operation, the CTIS is operative to maintain the wheel valve assembly in a normally closed position when air pressure to the inlet port is at atmospheric pressure. When a sufficient positive air pressure is supplied to the inlet port, the valve assembly assumes an open position connecting the inlet port to the outlet port to inflate the tire. When a negative air pressure is supplied to the inlet port, the valve assembly assumes an exhaust position connecting the outlet port to the exhaust port to deflate the tire.